This time of year, yes. We have monsoons that roll through in the late afternoon usually in lower elevations. The higher elevations say above 8-9000' is really a crap shoot any time of year. That said riding in the occasional sprinkle isn't bad, but many times those storms will bring marble sized hail and lightning. It can get downright scary, so come prepared.
Trust me you will have absolutely no problem finding a plan "B". NM is a most underrated MTB mecca as far as I'm concerned!
Trust me you will have absolutely no problem finding a plan "B". NM is a most underrated MTB mecca as far as I'm concerned!